Here we go again. A good result and performance is yet again followed by a disheartening defeat.

Yes, Wednesday's Carling Cup semi-final, second leg had to take priority, but that doesn't explain some baffling changes to the starting line-up instigated by Steve McClaren on Saturday.

OK, Gareth Southgate and Ugo Ehiogu were sidelined through injury, but was it wise to ask two defenders to play out of position?

Franck Queudrue moved across from left-back to partner Chris Riggott in the centre, while in-form Stuart Parnaby, a right-footer, stood in for the Frenchman.

Surely a safer option would have been to ask Parnaby to play on the right, leave Queudrue in his usual slot and move Danny Mills alongside Riggott?

Mills proved on many occasions with Leeds United that he's a more than capable central defender.

Or, yet another alternative, give Andrew Davies, an England Under 20 centre-back, the chance to make amends for an uncharacteristically below-par display against Leicester.

What a boost it would have given this talented teenager to be asked to nullify Dennis Bergkamp's undoubted threat.

Would any of the alternatives have worked any better? We'll never know; it's easy, after all, to pick teams and systems from the safety of the stands.

But if Southgate and Ehiogu, two of England's finest stoppers, struggled to contain Arsenal's rampant attack a fortnight ago, it was always going to be unlikely that a makeshift defence would cope any better.

After the game, the manager admitted his side conceded poor goals from a defensive point of view, which suggests he'll make alterations for Wednesday.

Boro may have shipped sloppy goals, but Arsenal's dominance of midfield provided the bedrock for their 4-1 success.

Doriva was sorely missed. George Boateng was tireless in the holding role, but had precious little in the way of support. But for his silly sending off, he would have been Boro's man of the match.

Bolo Zenden is not a central midfielder of the class of Vieira and Edu or, for that matter, Doriva, and struggled to keep up with the pace of the game.

Out on the flanks, Stewart Downing had a quiet game by his recent, promising standards and caused Lauren few problems, while his corners lacked their usual pace and accuracy.

Gaizka Mendieta was virtually anonymous on the right and was totally overshadowed by his Arsenal counterpart Ray Parlour, one of the Premiership's most under-rated talents.

So what of the attack? Well, Joseph Job scored an absolute blinder, chesting down Michael Ricketts' clever header following a Queudrue free-kick before lashing his shot into the roof of Arsenal's net.

But his sidekick Ricketts struggled to get into the game.

That the pair started must have mystified Juninho and Massimo Maccarone, who had arguably their best games of the season in Tuesday's 1-0 Carling Cup win.

Chances are the Little Fella and Job will start on Wednesday, but an opportunity to allow Maccarone to build up his fragile confidence was squandered at the weekend.

Nevertheless, Arsenal were outstanding on the day. Their goals exuded class, as well as no small amount of grit.

Parlour out-muscled Parnaby before hitting a slide-rule pass/cross to Bergkamp and the Dutchman's first-time shot found the net via Riggott's despairing outstretched leg on 19 minutes.

Boro's equaliser four minutes later was a brief ray of light, but that was snuffed out when Freddie Ljungberg wrong-footed the visiting defence with a clever drag-back and poked the ball under Queudrue and through Mark Schwarzer's legs.

It was one-way traffic after the break with Ljungberg extending Arsenal's lead with a close-range header from Robert Pires' 67th-minute corner.

David Bentley completed the rout when he audaciously chipped Schwarzer from 20 yards in the 90th minute.

McClaren must now lift his troops, remind them they can play much, much better than they did on Saturday and, crucially, they know they can beat Arsenal.